From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_NONE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 5CFDB1F4C0 for ; Thu, 17 Oct 2019 06:24:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404747AbfJQGYf (ORCPT ); Thu, 17 Oct 2019 02:24:35 -0400 Received: from cloud.peff.net ([104.130.231.41]:50504 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1727653AbfJQGYf (ORCPT ); Thu, 17 Oct 2019 02:24:35 -0400 Received: (qmail 21096 invoked by uid 109); 17 Oct 2019 06:24:35 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Thu, 17 Oct 2019 06:24:35 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 6215 invoked by uid 111); 17 Oct 2019 06:27:39 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.94) with (TLS_AES_256_GCM_SHA384 encrypted) ESMTPS; Thu, 17 Oct 2019 02:27:39 -0400 Authentication-Results: peff.net; auth=none Date: Thu, 17 Oct 2019 02:24:34 -0400 From: Jeff King To: Jonathan Tan Cc: stolee@gmail.com, git@vger.kernel.org, mh@glandium.org Subject: Re: [PATCH 3/6] index-pack: remove redundant child field Message-ID: <20191017062433.GC10862@sigill.intra.peff.net> References: <67ca2f70-361a-bebd-7590-37337959552c@gmail.com> <20191010190229.100750-1-jonathantanmy@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191010190229.100750-1-jonathantanmy@google.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Thu, Oct 10, 2019 at 12:02:29PM -0700, Jonathan Tan wrote: > > On 10/9/2019 7:44 PM, Jonathan Tan wrote: > > > Instead, recompute ancestry if we ever need to reclaim memory. > > > > I find this message lacking in important details: > > > > 1. Where do we recompute ancestry? > > 2. What are the performance implications of this change? > > 3. Why is it important that you construct a stack of deltas in prune_base_data()? > > Thanks for taking a look at this. My original plan (as I perhaps badly > explained in the cover letter [1]) was to show the individual small > steps that I took to reach the end goal, each step still passing all > tests, in the hope that small steps are easier to understand than one > big one. Hence why I didn't explain much in this commit message (and > others), because I thought that I might have to squash them later. But > perhaps that is too confusing and I should have just squashed them in > the first place (and explain all the changes in the commit message - > it's +177 -198, which is not too big anyway). FWIW, I like the breakdown. These are tricky cleanups, and seeing them individually makes it easy to verify that they don't themselves break anything. I think they just need more explanation. -Peff